commit b29c1530c7864ddfe382b18f4fc6e88eb46c1595 Author: Nick Mathewson nickm@torproject.org Date: Fri Oct 17 17:06:31 2014 -0400

Refactor link handshake cell type implementations to use trunnel

Unit tests still pass. --- src/or/channeltls.c | 138 +++++++++++++++++++++-------------------------- src/or/connection_or.c | 139 ++++++++++++++++++++++++++++++------------------ 2 files changed, 148 insertions(+), 129 deletions(-)

diff --git a/src/or/channeltls.c b/src/or/channeltls.c index af63444..0376e74 100644 --- a/src/or/channeltls.c +++ b/src/or/channeltls.c @@ -24,6 +24,7 @@ #include "connection.h" #include "connection_or.h" #include "control.h" +#include "link_handshake.h" #include "relay.h" #include "router.h" #include "routerlist.h" @@ -1740,13 +1741,14 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) STATIC void channel_tls_process_certs_cell(var_cell_t *cell, channel_tls_t *chan) { - tor_x509_cert_t *link_cert = NULL; - tor_x509_cert_t *id_cert = NULL; - tor_x509_cert_t *auth_cert = NULL; - uint8_t *ptr; +#define MAX_CERT_TYPE_WANTED OR_CERT_TYPE_AUTH_1024 + tor_x509_cert_t *certs[MAX_CERT_TYPE_WANTED + 1]; int n_certs, i; + certs_cell_t *cc = NULL; + int send_netinfo = 0;

+ memset(certs, 0, sizeof(certs)); tor_assert(cell); tor_assert(chan); tor_assert(chan->conn); @@ -1776,63 +1778,41 @@ channel_tls_process_certs_cell(var_cell_t *cell, channel_tls_t *chan) if (cell->circ_id) ERR("It had a nonzero circuit ID");

- n_certs = cell->payload[0]; - ptr = cell->payload + 1; + if (certs_cell_parse(&cc, cell->payload, cell->payload_len) < 0) + ERR("It couldn't be parsed."); + + n_certs = cc->n_certs; + for (i = 0; i < n_certs; ++i) { - uint8_t cert_type; - uint16_t cert_len; - if (cell->payload_len < 3) - goto truncated; - if (ptr > cell->payload + cell->payload_len - 3) { - goto truncated; - } - cert_type = *ptr; - cert_len = ntohs(get_uint16(ptr+1)); - if (cell->payload_len < 3 + cert_len) - goto truncated; - if (ptr > cell->payload + cell->payload_len - cert_len - 3) { - goto truncated; - } - if (cert_type == OR_CERT_TYPE_TLS_LINK || - cert_type == OR_CERT_TYPE_ID_1024 || - cert_type == OR_CERT_TYPE_AUTH_1024) { - tor_x509_cert_t *cert = tor_x509_cert_decode(ptr + 3, cert_len); - if (!cert) { - log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, - "Received undecodable certificate in CERTS cell from %s:%d", - safe_str(chan->conn->base_.address), - chan->conn->base_.port); + certs_cell_cert_t *c = certs_cell_get_certs(cc, i); + + uint16_t cert_type = c->cert_type; + uint16_t cert_len = c->cert_len; + uint8_t *cert_body = certs_cell_cert_getarray_body(c); + + if (cert_type > MAX_CERT_TYPE_WANTED) + continue; + + tor_x509_cert_t *cert = tor_x509_cert_decode(cert_body, cert_len); + if (!cert) { + log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, + "Received undecodable certificate in CERTS cell from %s:%d", + safe_str(chan->conn->base_.address), + chan->conn->base_.port); + } else { + if (certs[cert_type]) { + tor_x509_cert_free(cert); + ERR("Duplicate x509 certificate"); } else { - if (cert_type == OR_CERT_TYPE_TLS_LINK) { - if (link_cert) { - tor_x509_cert_free(cert); - ERR("Too many TLS_LINK certificates"); - } - link_cert = cert; - } else if (cert_type == OR_CERT_TYPE_ID_1024) { - if (id_cert) { - tor_x509_cert_free(cert); - ERR("Too many ID_1024 certificates"); - } - id_cert = cert; - } else if (cert_type == OR_CERT_TYPE_AUTH_1024) { - if (auth_cert) { - tor_x509_cert_free(cert); - ERR("Too many AUTH_1024 certificates"); - } - auth_cert = cert; - } else { - tor_x509_cert_free(cert); - } + certs[cert_type] = cert; } } - ptr += 3 + cert_len; - continue; - - truncated: - ERR("It ends in the middle of a certificate"); }

+ tor_x509_cert_t *id_cert = certs[OR_CERT_TYPE_ID_1024]; + tor_x509_cert_t *auth_cert = certs[OR_CERT_TYPE_AUTH_1024]; + tor_x509_cert_t *link_cert = certs[OR_CERT_TYPE_TLS_LINK]; + if (chan->conn->handshake_state->started_here) { int severity; if (! (id_cert && link_cert)) @@ -1881,7 +1861,7 @@ channel_tls_process_certs_cell(var_cell_t *cell, channel_tls_t *chan) safe_str(chan->conn->base_.address), chan->conn->base_.port);

chan->conn->handshake_state->id_cert = id_cert; - id_cert = NULL; + certs[OR_CERT_TYPE_ID_1024] = NULL;

if (!public_server_mode(get_options())) { /* If we initiated the connection and we are not a public server, we @@ -1908,7 +1888,7 @@ channel_tls_process_certs_cell(var_cell_t *cell, channel_tls_t *chan)

chan->conn->handshake_state->id_cert = id_cert; chan->conn->handshake_state->auth_cert = auth_cert; - id_cert = auth_cert = NULL; + certs[OR_CERT_TYPE_ID_1024] = certs[OR_CERT_TYPE_AUTH_1024] = NULL; }

chan->conn->handshake_state->received_certs_cell = 1; @@ -1922,9 +1902,10 @@ channel_tls_process_certs_cell(var_cell_t *cell, channel_tls_t *chan) }

err: - tor_x509_cert_free(id_cert); - tor_x509_cert_free(link_cert); - tor_x509_cert_free(auth_cert); + for (unsigned i = 0; i < ARRAY_LENGTH(certs); ++i) { + tor_x509_cert_free(certs[i]); + } + certs_cell_free(cc); #undef ERR }

@@ -1943,7 +1924,7 @@ STATIC void channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan) { int n_types, i, use_type = -1; - uint8_t *cp; + auth_challenge_cell_t *ac = NULL;

tor_assert(cell); tor_assert(chan); @@ -1956,7 +1937,7 @@ channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan) safe_str(chan->conn->base_.address), \ chan->conn->base_.port, (s)); \ connection_or_close_for_error(chan->conn, 0); \ - return; \ + goto done; \ } while (0)

if (chan->conn->base_.state != OR_CONN_STATE_OR_HANDSHAKING_V3) @@ -1969,19 +1950,17 @@ channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan) ERR("We already received one"); if (!(chan->conn->handshake_state->received_certs_cell)) ERR("We haven't gotten a CERTS cell yet"); - if (cell->payload_len < OR_AUTH_CHALLENGE_LEN + 2) - ERR("It was too short"); if (cell->circ_id) ERR("It had a nonzero circuit ID");

- n_types = ntohs(get_uint16(cell->payload + OR_AUTH_CHALLENGE_LEN)); - if (cell->payload_len < OR_AUTH_CHALLENGE_LEN + 2 + 2*n_types) - ERR("It looks truncated"); + if (auth_challenge_cell_parse(&ac, cell->payload, cell->payload_len) < 0) + ERR("It was not well-formed."); + + n_types = ac->n_methods;

/* Now see if there is an authentication type we can use */ - cp = cell->payload+OR_AUTH_CHALLENGE_LEN + 2; - for (i = 0; i < n_types; ++i, cp += 2) { - uint16_t authtype = ntohs(get_uint16(cp)); + for (i = 0; i < n_types; ++i) { + uint16_t authtype = auth_challenge_cell_get_methods(ac, i); if (authtype == AUTHTYPE_RSA_SHA256_TLSSECRET) use_type = authtype; } @@ -1992,7 +1971,7 @@ channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan) /* If we're not a public server then we don't want to authenticate on a connection we originated, and we already sent a NETINFO cell when we got the CERTS cell. We have nothing more to do. */ - return; + goto done; }

if (use_type >= 0) { @@ -2006,7 +1985,7 @@ channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan) log_warn(LD_OR, "Couldn't send authenticate cell"); connection_or_close_for_error(chan->conn, 0); - return; + goto done; } } else { log_info(LD_OR, @@ -2019,9 +1998,12 @@ channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan) if (connection_or_send_netinfo(chan->conn) < 0) { log_warn(LD_OR, "Couldn't send netinfo cell"); connection_or_close_for_error(chan->conn, 0); - return; + goto done; }

+done: + auth_challenge_cell_free(ac); + #undef ERR }

@@ -2038,7 +2020,7 @@ channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan) STATIC void channel_tls_process_authenticate_cell(var_cell_t *cell, channel_tls_t *chan) { - uint8_t expected[V3_AUTH_FIXED_PART_LEN]; + uint8_t expected[V3_AUTH_FIXED_PART_LEN+256]; const uint8_t *auth; int authlen;

@@ -2094,11 +2076,13 @@ channel_tls_process_authenticate_cell(var_cell_t *cell, channel_tls_t *chan) if (authlen < V3_AUTH_BODY_LEN + 1) ERR("Authenticator was too short");

- if (connection_or_compute_authenticate_cell_body( - chan->conn, expected, sizeof(expected), NULL, 1) < 0) + ssize_t bodylen = + connection_or_compute_authenticate_cell_body( + chan->conn, expected, sizeof(expected), NULL, 1); + if (bodylen < 0 || bodylen != V3_AUTH_FIXED_PART_LEN) ERR("Couldn't compute expected AUTHENTICATE cell body");

- if (tor_memneq(expected, auth, sizeof(expected))) + if (tor_memneq(expected, auth, bodylen)) ERR("Some field in the AUTHENTICATE cell body was not as expected");

{ diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 8602bcb..ba30987 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -30,6 +30,7 @@ #include "entrynodes.h" #include "geoip.h" #include "main.h" +#include "link_handshake.h" #include "networkstatus.h" #include "nodelist.h" #include "reasons.h" @@ -2279,28 +2280,37 @@ connection_or_send_certs_cell(or_connection_t *conn) int connection_or_send_auth_challenge_cell(or_connection_t *conn) { - var_cell_t *cell; - uint8_t *cp; - uint8_t challenge[OR_AUTH_CHALLENGE_LEN]; + var_cell_t *cell = NULL; + int r = -1; tor_assert(conn->base_.state == OR_CONN_STATE_OR_HANDSHAKING_V3);

if (! conn->handshake_state) return -1;

- if (crypto_rand((char*)challenge, OR_AUTH_CHALLENGE_LEN) < 0) - return -1; - cell = var_cell_new(OR_AUTH_CHALLENGE_LEN + 4); + auth_challenge_cell_t *ac = auth_challenge_cell_new(); + + if (crypto_rand((char*)ac->challenge, sizeof(ac->challenge)) < 0) + goto done; + + auth_challenge_cell_add_methods(ac, AUTHTYPE_RSA_SHA256_TLSSECRET); + auth_challenge_cell_set_n_methods(ac, + auth_challenge_cell_getlen_methods(ac)); + + cell = var_cell_new(auth_challenge_cell_encoded_len(ac)); + ssize_t len = auth_challenge_cell_encode(cell->payload, cell->payload_len, + ac); + if (len != cell->payload_len) + goto done; cell->command = CELL_AUTH_CHALLENGE; - memcpy(cell->payload, challenge, OR_AUTH_CHALLENGE_LEN); - cp = cell->payload + OR_AUTH_CHALLENGE_LEN; - set_uint16(cp, htons(1)); /* We recognize one authentication type. */ - set_uint16(cp+2, htons(AUTHTYPE_RSA_SHA256_TLSSECRET));

connection_or_write_var_cell_to_buf(cell, conn); + r = 0; + + done: var_cell_free(cell); - memwipe(challenge, 0, sizeof(challenge)); + auth_challenge_cell_free(ac);

- return 0; + return r; }

/** Compute the main body of an AUTHENTICATE cell that a client can use @@ -2327,19 +2337,18 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn, crypto_pk_t *signing_key, int server) { - uint8_t *ptr; + auth1_t *auth = NULL; + auth_ctx_t *ctx = auth_ctx_new(); + int result;

/* assert state is reasonable XXXX */

- if (outlen < V3_AUTH_FIXED_PART_LEN || - (!server && outlen < V3_AUTH_BODY_LEN)) - return -1; + ctx->is_ed = 0;

- ptr = out; + auth = auth1_new();

/* Type: 8 bytes. */ - memcpy(ptr, "AUTH0001", 8); - ptr += 8; + memcpy(auth1_getarray_type(auth), "AUTH0001", 8);

{ const tor_x509_cert_t *id_cert=NULL, *link_cert=NULL; @@ -2359,12 +2368,10 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn, server_id = server ? my_id : their_id;

/* Client ID digest: 32 octets. */ - memcpy(ptr, client_id, 32); - ptr += 32; + memcpy(auth->cid, client_id, 32);

/* Server ID digest: 32 octets. */ - memcpy(ptr, server_id, 32); - ptr += 32; + memcpy(auth->sid, server_id, 32); }

{ @@ -2378,12 +2385,10 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn, }

/* Server log digest : 32 octets */ - crypto_digest_get_digest(server_d, (char*)ptr, 32); - ptr += 32; + crypto_digest_get_digest(server_d, (char*)auth->slog, 32);

/* Client log digest : 32 octets */ - crypto_digest_get_digest(client_d, (char*)ptr, 32); - ptr += 32; + crypto_digest_get_digest(client_d, (char*)auth->clog, 32); }

{ @@ -2396,49 +2401,79 @@ connection_or_compute_authenticate_cell_body(or_connection_t *conn, freecert = tor_tls_get_peer_cert(conn->tls); cert = freecert; } - if (!cert) - return -1; - memcpy(ptr, tor_x509_cert_get_cert_digests(cert)->d[DIGEST_SHA256], 32); + if (!cert) { + log_warn(LD_OR, "Unable to find cert when making AUTH1 data."); + goto err; + } + + memcpy(auth->scert, + tor_x509_cert_get_cert_digests(cert)->d[DIGEST_SHA256], 32);

if (freecert) tor_x509_cert_free(freecert); - ptr += 32; }

/* HMAC of clientrandom and serverrandom using master key : 32 octets */ - tor_tls_get_tlssecrets(conn->tls, ptr); - ptr += 32; - - tor_assert(ptr - out == V3_AUTH_FIXED_PART_LEN); - - if (server) - return V3_AUTH_FIXED_PART_LEN; // ptr-out + tor_tls_get_tlssecrets(conn->tls, auth->tlssecrets);

/* 8 octets were reserved for the current time, but we're trying to get out * of the habit of sending time around willynilly. Fortunately, nothing * checks it. That's followed by 16 bytes of nonce. */ - crypto_rand((char*)ptr, 24); - ptr += 24; + crypto_rand((char*)auth->rand, 24); + + ssize_t len; + if ((len = auth1_encode(out, outlen, auth, ctx)) < 0) { + log_warn(LD_OR, "Unable to encode signed part of AUTH1 data."); + goto err; + }

- tor_assert(ptr - out == V3_AUTH_BODY_LEN); + if (server) { + auth1_t *tmp = NULL; + ssize_t len2 = auth1_parse(&tmp, out, len, ctx); + if (!tmp) { + log_warn(LD_OR, "Unable to parse signed part of AUTH1 data."); + goto err; + } + result = (int) (tmp->end_of_fixed_part - out); + auth1_free(tmp); + if (len2 != len) { + log_warn(LD_OR, "Mismatched length when re-parsing AUTH1 data."); + goto err; + } + goto done; + }

- if (!signing_key) - return V3_AUTH_BODY_LEN; // ptr - out + if (signing_key) { + auth1_setlen_sig(auth, crypto_pk_keysize(signing_key));

- { - int siglen; char d[32]; - crypto_digest256(d, (char*)out, ptr-out, DIGEST_SHA256); - siglen = crypto_pk_private_sign(signing_key, - (char*)ptr, outlen - (ptr-out), + crypto_digest256(d, (char*)out, len, DIGEST_SHA256); + int siglen = crypto_pk_private_sign(signing_key, + (char*)auth1_getarray_sig(auth), + auth1_getlen_sig(auth), d, 32); - if (siglen < 0) + if (siglen < 0) { + log_warn(LD_OR, "Unable to sign AUTH1 data."); return -1; + }

- ptr += siglen; - tor_assert(ptr <= out+outlen); - return (int)(ptr - out); + auth1_setlen_sig(auth, siglen); + + len = auth1_encode(out, outlen, auth, ctx); + if (len < 0) { + log_warn(LD_OR, "Unable to encode signed AUTH1 data."); + goto err; + } } + result = (int) len; + goto done; + + err: + result = -1; + done: + auth1_free(auth); + auth_ctx_free(ctx); + return result; }

/** Send an AUTHENTICATE cell on the connection <b>conn</b>. Return 0 on